Form the screws locking the tire rim to a wheel disk, the bending spanner is used to drive the screw. This is because the screws are embedded into recesses. The surface of the tire rim is not flat so that the general used spanner is not suitable for driving the screws to lock a tire.
A bending spanner has a handle and a driving portion. A connecting portion serves to connect the handle and the driving portion. The driving portion has an engaging head. The engaging head has an engaging end for receiving a sleeve. The connecting portion cause that the driving portion is inclined to the handle. The engaging head has teeth for engaging the driving portion. In the prior art, the recess for embedding a screw is too deep, the driving portion can not be sufficiently inserted into the recess for driving the screw. As a result, the nut cannot be tightly engaged.
Moreover, in driving the nut, a react force is applied to the spanner and thus the engaging head will be damaged if it is used for a long time. If the engaging head is too long, it is possible that the engaging head will deform or damages so as to affect the lifetime of the product.